The present invention relates to an improved heat exchanger coil which utilizes evaporative cooling, and more particularly, to a condenser unit that provides for a higher volumetric airflow within the heat exchanger with reduced pressure drop to increase the heat exchanger efficiency.
Heat exchangers which are commonly used as condensing units in refrigeration systems, such as for industrial air conditioning, are known. One such heat exchanger which is described in detail in U.S. Pat. Nos. 5,501,269 and 5,787,722, which are assigned to the assignee of the present invention and are incorporated herein by reference as if fully set forth, utilize evaporative cooling of spiral coils located within a heat exchanger housing. Water is sprayed onto the heat exchange coils solely from above or from the top and through the middle and travels downwardly through the coils providing evaporative cooling. At the same time, air is drawn through the pathways located in the outer housing walls to the base of the heat exchange unit and then upwardly through the spiral coils by a fan or blower to increase the evaporative cooling efficiency.
To provide for maximum heat transfer, it is desirable to provide as much surface area as possible for each of the spiral cooling coils while still allowing sufficient space for the travel of water droplets downwardly through the spiral coils as well as upward airflow. Using these known parameters, the coil spacing has been maximized to provide efficient cooling for the refrigerant carried in the coils. Closer radial spacing of the coils results in a higher pressure drop across the coils for a given fan or blower airflow rating which ultimately leads to reduced efficiency beyond a point of maximization.
It would be desirable to provide further improvements in the efficiency of such heat exchanger units to increase the cooling capacity of the heat exchanger as well as reduce cooling costs.